The first reproduction

[FlareBlitz]

Again I'll say that we aren't looking at that scope, we're looking at it from a standpoint of reproducingbeing a negative thing on a one generation standpoint and is that negative enough to cause the axe to fall (which it did more often than not, I'm guessing).

But that's the scope we should be looking at it from. There are way too many examples of behaviors that are detrimental to an individual but beneficial from the perspective of the species for me to list here, but suffice to say that cases of organisms doing apparently self-destructive things and passing on that tendency to offspring are well-documented, primarily because the societies/species with those organisms tend to have statistically better survival rates, meaning that their offspring are more likely to survive than if they were purely selfish.

It's technically not a disadvantage until they actually reproduce though, so perhaps that is the key to all this.

This is exactly what I was getting at. The competitive disadvantage doesn't become apparent or even significant until all the organisms less inclined to reproduce have already died out, at which point the tendency to reproduce permeates the gene pool.

 

[Morm]

This is exactly what I was getting at. The competitive disadvantage doesn't become apparent or even significant until all the organisms less inclined to reproduce have already died out, at which point the tendency to reproduce permeates the gene pool.

Actually it becomes apparent and significant immediately after the first reproduction and has little to do with the dying off of non reproducers.

I am honestly of the opinion now that, thanks to auto assemblers, it's pretty much assured that breeding came first not last.

 

[FlareBlitz]

Actually it becomes apparent and significant immediately after the first reproduction and has little to do with the dying off of non reproducers.

Not really sure how you can say this. Evolution is a process of successive genetic changes which takes literally generations to have any sort of meaningful impact on an organism's practical phenotype. A bacteria losing resources immediately upon reproduction has little impact on its long term survival rate; it's merely a dip in its equilibrium state. It can just metabolize more and regain its original energy levels quickly. It would take a genetic disadvantage, a rapid change in its environment (you could argue that an offspring would qualify as this due to the competition) or some sort of permenant crippling damage to have any sort of substantial impact on the survival prospects of its genetic line.

 

[breh]

Well, my guess is similar (vaguely) to what FlareBlitz said in his first post..

Imagine that every (for instance) 100 years on a lifeless earth, a single organism was formed in the primordial seas.

The first organism was unable to reproduce. It lived for a few days, then died to radiation.
The second organism was also unable to reproduce. It also lived for a day or two before dying to radiation.

Fast forward to the 103rd organism. This organism is able to reproduce. While it provides compteition for itself, it allows itself to live on in a way. I'm not saying that it leaves behind a "legacy", but that it allows the organism to survive in the environment (despite the difficulty of surviving in general) and (so to speak) artificially lengthen its lifespan... One cell has a short lifespan but the more there are, the greater their lifespan is.

Did that make any sense? xD

 

[Deck Knight]

I think the most important element of the first reproducers is the lack of predation. What exactly is the threat of the non-reproducers to the producers? If the non-reproducers cannot interfere with reproducers in any significant way, then on a one-generation basis the disadvantage is only on paper. The inefficiency involved in reproduction is irrelevant because there is no immediate threat to reproducers, and thus they prevail. Given they will be the only species to continue to exist after a fairly short period of time, short of traits like cannibalism or overutilization of surrounding resources making them die before the next reproduction, the organism "succeeds."

A more interesting aspect of this is that continous life eats up resources infinitely. In the end everything dies but you can't really approach life forms fatalistically. Reproduction is value nuetral to the indivual parent(s) but positive for the species. The genes have successfully enacted their coding and begotten more of themselves.

I think the question we're looking for is "what is the failure or success condition for a species?"

 

[cantab]

On-topic article in the latest issue of New Scientist, about the origin of life. I might post scans later.

 

[Morm]

Do it Cantab!

Deck I think you missed the original point. The idea was that reproduction is a discrete negative in the shortest term thinking and might have given issue with survivability (not just against predators). Also the first organisms included cyanobacteria, but that's not to say things weren't around consuming them.

 

[Scoopapa]

I think asking what the first organism to reproduce was is sort of asking the wrong question. The first organism to reproduce was...the first organism. There is no way for there to have been an organism that didn't reproduce - where did it come from? Where did it inherit it's genes? Without reproduction, life would actually be subject to something similar to the probabilities that creationists commonly use to try to refute evolution (something similar because their numbers are made up, even if they know what they're trying to portray - the old "tornado in a junkyard" argument). The only processes that allow for that kind of complexity to occur are reproduction, variation, and natural selection. Thus, it is extremely likely that, long before there was a first organism, there was a naturally occurring chemistry that produced nearly identical copies of polymers. Considering that RNA readily forms a "negative" of itself in a soup of nucleobases, this is quite plausible. In fact I've covered some of how this works in better detail, and linked to a great video on the topic in previous posts in this thread, which nobody seems to have responded to.

At any rate, reproduction (or lack of) is the only driving force in what changes phenotypes. Other factors, such as finding food and not getting eaten, only matter insofar as they relate to reproduction. Reproduction is what started it all, and it's the only reason that any organism has any of it's helpful traits. The world is full of things that are good at procreating, and quickly loses things that are bad at it (some things lose out as the "metagame" shifts). Thus, it doesn't make sense to ask why something reproduces to it's own detriment. We survive to reproduce, we don't reproduce for our survival.

 

[Morm]

you're opening rhetoric is chicken vs egg. We know it started somewhere, infact I'd say the egg came about 300million years first (give or take)

 

[whistle]

cantab may be referring to this article

http://www.newscientist.com/article...e-to-understand-how-life-began.html?full=true

not to steal his thunder but no point in scanning when it's online

 

[cantab]

Yes, that is the correct article.

 

[Morm]

On the topic of the early Earth atmosphere and conditions, I've actually observed that life merely existing tended to terraform the Earth and make it more hospitable for more life. Kind of a neat idea.

 

[Scoopapa]

you're opening rhetoric is chicken vs egg. We know it started somewhere, infact I'd say the egg came about 300million years first (give or take)

I really hope that's not all you got from my post. Pointing out how a non-reproducing organism has no feasible way of coming into existence is not chicken vs egg "rhetoric". My opening "rhetoric" is meant to support the point that I make later in the post, so please don't get hung up on "hey that sounds sorta like chicken and egg". Also, the fact that the appearance of the egg predates the appearance of the chicken in evolutionary history...has nothing to do with my post. I hope you don't perceive it as hostility that I said you were asking the wrong question. I was trying to show you how you could alleviate your confusion by taking an evolutionary perspective, and realizing what does and doesn't drive change in life.

 

[Morm]

I think asking what the first organism to reproduce was is sort of asking the wrong question. The first organism to reproduce was...the first organism. There is no way for there to have been an organism that didn't reproduce - where did it come from? Where did it inherit it's genes? Without reproduction, life would actually be subject to something similar to the probabilities that creationists commonly use to try to refute evolution (something similar because their numbers are made up, even if they know what they're trying to portray - the old "tornado in a junkyard" argument)

that's where I got it from, it appeared to me like you were pleading a bit of a cause where the first organism had to reproduce because it had nowhere to come from, yet in order for THAT organism to reproduce, by the logic I got out of it, you'd need something begetting it.

 

[sonickid01]

There's a video series on youtube by a gentleman named cdk007 explaining abiogenesis and the origin of reproduction and many other topics. Let me see if I can paraphrase only off memory since I'm too lazy to rewatch any of the videos.

To answer your question on the origin of reproduction requires a delve into abiogenesis. The seas were an organic soup- that's a given. From there certain reactions would form and you'd get self-replicating structures, protein vesicles as a primitive "cell wall" which contain the other structures, long story short the precursor to cells. These structures would form presumably because of underwater currents due to hotspots and heat vents under the water. As the "organisms" are carried through the ocean by these currents they come closer and further from the heated areas and reactions occur again, often breaking bonds within the organic structures in the vesicle. If a vesicle gets split in half and part of the structures are distributed between the two product "organisms" then you've essentially gotten a division of a single "organism." This is the basic precursor to reproduction and is in some sense unintentional as merely a product of reactions. That's not to say it was a "cosmic accident" as some would be happy to describe it, but it was a process which happened to occur and took hold from there. The vesicles containing structures which would repair damaged parts of the system to a not-broken and stable state would become more common through a population, and those that have structures which would happen to split up their replicating structures evenly so that the "daughter" products both could "reproduce" successfully would also become dominant. Thus, we get a crude form of reproduction and evolution just takes it and runs.

So in some sense it wasn't a question of whether a fully formed organism as we term it today could survive with reproduction, but the most primitive ancestor to reproduction was actually there first as part of natural processes involving chemical reactions and currents of water. It's really quite amazing. I don't know how well-set and tested the explanation is exactly but still, it makes sense.

Since I'm simply going off of my memory, here's cdk007's videos for those who are interested:
Abiogenesis: http://www.youtube.com/watch?v=U6QYDdgP9eg
Genetic Code: http://www.youtube.com/watch?v=rtmbcfb_rdc

If I botched part of the explanation feel free to point and laugh and correct me :P

 

[Scoopapa]

@SonicKid

The vesicles are made of naturally occurring fatty acids (not proteins), which can be found in the very same clay that the nitrogen bases (nucleobases), which automatically polymerize to form the "structures" you describe are also found. The fatty acids automatically form vesicles because they are long chains that are insoluble in water. Thus, when they come together, they tend to line up next to each other. Eventually this forms a sheet, which forms a sphere when its inevitable wobbling causes two of its sides to meet. The cool thing about this is that freely floating nucleobases can fit through the membrane, but when they start polymerizing, they no longer can. They can still form a double chain by attaching to freely floating nucleobases in the "soup", but when the chains split off again, the new chain is stuck too. This is how the vesicles come to have their own specific code, becuase the RNA fragments get stuck inside, but keep replicating.

So...hahahahaha! (j/k : P)

 

[sonickid01]

Ah yeah, that's correct. I couldn't remember the lipids :P *shot*

So yeah the fact that all the vesicles contain a unique "code" of RNA fragments and the way that the vesicles can split due to the currents would give rise to reproduction in these borderline non-living pieces of organic matter. They don't really need a lot of resources to survive as they are stable enough to remain "alive" during their cycle through the currents so the question of creating competition really doesn't apply at this time. When they do start needing additional resources, the oceans are probably large enough and dense with organic compounds that it's not like two vesicles need to face head-on conflict over nutrients, it's plenty for everyone.

 

[popololvic]

Proof by the absurd:
let A be the tactic where the lifeform doesn't reproduce.
Proposition 1¨if a lifeform apply A, then it is dominant to other lifeforms with non-A living simultaneously¨
Define dominant: since the ¨power¨ of genes is to exist for the longest time possible (simply put), then we can consider the lifetime as a valuable measure.
If we admit that both of these lifestyles were simultaneously existing, proposition 1 fails as we can clearly see that reproductive lifeforms are dominant in the sense were a certain gene had the ability to mutate and adapt for the environment whereas the gene of non reproductive lifeforms couldn't...
Some theories for reproduction:
-a theory states that sexual reproduction facilitates mechanisms for repair and chromosomal segregation.
-sexual recombination brings beneficial mutations together so that they can be expressed in the population
-sexual reproduction purges the genome of
harmful mutations

As I understand it, the genes are master and creator of the metabolisms in a given body for it has to survive it must evolve and repair and adapt: reproduction is the way to go